About the creation of proton-anti-proton pair at electron-positron collider in the energy range of the mass $\Psi (3770)$

Abstract

The process of electron--positron annihilation into proton--antiproton pair is considered within the vicinity of $\psi (3770)$ resonance. The interference between the pure electromagnetic intermediate state and the $\psi (3770)$ state is evaluated. It is shown that this interference is destructive and the relative phase between these two contributions is large (${\varphi }_0\approx 250^o$).

Comments: 16 pages, 6 figures. The authors included the long-range contributions (D-meson loop) in their calculations. The conclusion of the papers did not change